The problem isn't your computers, or the file itself, it's a virus that's living within your network.
My suggestion to you, is to go to a public library, college, or otherwise suitable location,a nd download the file.
Then, and only then if you continue to have problems will you be able to determine it to be something outside of your network. Don't blame tony, or the webhost unless you actually KNOW what you're talking about like I do. I've worked on security for networks, and computers for over ten years, and trust me, it sounds like you've got yourself a linux based virus that's living in your router.